A rolling bearing is intended to be mounted in a housing of a mechanical system, between a fixed mechanical element and a rotary mechanical element so as to support the relative rotation thereof.
The design of a rolling bearing, more specifically the type of rolling bearing, the number of rows of rolling elements, the type of rolling elements, the size of the races and of the rolling elements, depends on the application of the mechanical system. The conditions relating to torque, rotational speed, load, environment or even the available space in the housing have an effect on the rolling bearing and are thus design constraints therefor.
However, manufacturers of mechanical systems and/or rolling bearings can change their ranges and lose compatibility.
The features of a rolling bearing may have been improved, but it still has the same housing, whereas a housing with smaller dimensions could be suitable.